media: rockchip/rga: constify video_device structure

[linux-2.6-block.git] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index 072139579d897021e83fe6b70344ad4acd62d664..4ad2d293ddc2605d2ae44ce075de68beb93841e0 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1537,10 +1537,15 @@ static vm_fault_t insert_pfn(struct vm_area_struct *vma, unsigned long addr,
                         * in may not match the PFN we have mapped if the
                         * mapped PFN is a writeable COW page.  In the mkwrite
                         * case we are creating a writable PTE for a shared
-                        * mapping and we expect the PFNs to match.
+                        * mapping and we expect the PFNs to match. If they
+                        * don't match, we are likely racing with block
+                        * allocation and mapping invalidation so just skip the
+                        * update.
                         */
-                       if (WARN_ON_ONCE(pte_pfn(*pte) != pfn_t_to_pfn(pfn)))
+                       if (pte_pfn(*pte) != pfn_t_to_pfn(pfn)) {
+                               WARN_ON_ONCE(!is_zero_pfn(pte_pfn(*pte)));
                                goto out_unlock;
+                       }
                        entry = *pte;
                        goto out_mkwrite;
                } else